物理学报Issue(21)：68-73,6.DOI:10.7498/aps.63.213101
氢化铁的自旋极化效应及势能函数
Spin polarization and potential energy function of FeH2
摘要
Abstract
Among the three methods (B3LYP, BP86 and B3LYP) in density functional theory (DFT), the best tools for predicting the ground state of metal hydride, the B3LYP method for predicting the harmonic frequencies and geometric parameters of the ground state of FeH2 gives result in good accordance with the experimental data;so it is employed to optimize the structure of molecules FeH and FeH2 in possible geometries and multiplicities based on 6-311++g(d,p) level in searching of the structure with the lowest energy. Results show that their electronic states in the ground states are FeH(4∆) and FeH2(5A1), supposing that the two molecules have three and four unpaired electrons respectively, with spin polarization effect, and they are paramagnetic substances, and the stable structure of molecule FeH2 is of C2v symmetry. The Murrell-Sorbie potential energy function-the sufficient analytical potential function form for biatomic molecules-with 4 parameters in molecule FeH is derived via the least square method. Their spectra data and force constants are deduced according to the results. The analytical potential energy function of FeH2 is also obtained from the many-body expansion theory, which gives the analytical potential function of triatom molecules of the single-value potential surface consisting of three parts with single body terms, two body terms, and three body terms. The deduced analytical functions for FeH2 in this paper predict successfully a global minimum stable structure of quintet FeH2 with a 4.68 eV depth potential trap, and other higher energy stable and saddle structures. This potential function predicts the balanced ground structure and the second derivative force constants of this molecule. According to the potential function of FeH2(C2v), when it is formed from H and FeH, a potential trap with its depth being 4.68 eV is excited and the complex molecule of H-Fe-H is easily formed. The reaction of Fe+H2→HFeH is exothermic with∆H =-0.08305 eV.关键词
氢化铁分子/密度泛函理论(DFT)/自旋极化/分析势能函数Key words
hydride iron/density functional theory (DFT)/spin polarization/potential energy function引用本文复制引用
郑圆圆,任桂明,陈锐,王兴明,谌晓洪,王玲,袁丽,黄晓凤..氢化铁的自旋极化效应及势能函数[J].物理学报,2014,(21):68-73,6.基金项目
四川省教育厅重点项目(批准号:14ZA0113)和西华大学研究生创新基金(批准号：ycjj2014127)资助的课题.* Project supported by the Key Fund Project of Department of Education Sichuan Province, China (Grant No.14ZA0113), and the Innovation Fund of Postgraduate, Xihua University, Sichuan Province, China (Grant No. ycjj2014127) （批准号:14ZA0113）
